Prime mover for marine propulsion.



' 0. (1. 011111 1; 11. L. 'L'OVELL.

PRIME MOVBR FOR MARINE PROPULSION APPLIGATION FILED MAY 15,1911.

" Patented 110 1.14, 1911 APPLICATION FILED HAY 15,1911

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0. G. CURTIS & R. L. LOVBLL. PRIME MOVER FOR MARINE PROPULSION.

APPLICATION FILED MAY 15,1911.

Patented Nov. 14, 1911.

W' nesss Inventors 4 @2 4 Q Attdrneys.

UNITED sTATEs PATENT o1 anion,

CHARLES G. CURTIS, OF, NEW Y ORK, N. Y., AND RALPH L. LOVELL, O] QUINCYMASSA- CHUSETTS.

PRIME MOVER FOR MARINE PROPULSION.

steam turbines so as to secure economy of fuel, particularly at cruisingspeeds. In carrying out our invent-ion we couple direct to the samepropeller shaft a. recip- -rocating engine and a steam turbine takingthe steam flow 1n SUCCSS1OIL at cruising speeds and adapted toutilize/the entire exansion down to a condenser vacuum. For igher speedsa art or all of the steam is by-passedf direct y from the boiler to the,steam turbine, and its complete expansion is utilized therein. V r

We prefer to use a steam turbine of the stage expansion, impulsetype, orone hav ing'initial impulse, pressure stages, with partial eri heralsteam admissiom'and pref- .erab y a so. having one or more final drumsta es. Aturbine of this character which wil be adapted to utilize thesteam pressure between the exhaust of thee-rigineand'the condenser, andwill also be adapted to iitilizethe full expansion of the steam.from-the boiler pressureto the condenser v pressure,

can be made with such sim licit-y o'f.-parts and, moderate length, thatt e-mountingof it directly on the same propeller shaft with thereclprocating engine 1s permissible. This combination has the furtheradvantage that a steam turbine having initial impulse, pressure stages,with partial peripheral steam admission, can, practically, be made toutilize the full expansion of the steam at alower shaft speed thantheordinary reaction turbine with f ull'peripheral admission,

and hence notonly can 'a higher propeller efliciency be secured, butthe' lower shaft 1 speed is better adapted to the conditions of e recirocating en ne,,which, in moderate speed s ips, can be ept connectedwith the propellershaft soas'to furnish power there- Specification ofLetters Patent. Application file (1 May 15,

Patented Nov. 14, 1911. 1911. Serial No. 627,114.

is preferably of the com )ound or two-cylinder type, a comparativelysimple form of engine, and since the fuil power it is required todevelop is less t ian that necessary to propel the shi at cruisi ag seed, it can be made small an being p1 ovi ed with large bearings andforced lubri nation, can 'be run with safety at quite high speeds.

In order to make the :ombination effective, a special relation bstweenthe en inc and the turbine must be provided. W hen .it is attempted toutilize :he fullexpansion in a turbine of the charar ter referred to, atall speeds and powers, tlTB efficiency of the early stages of theturtine becomes very 'poor at low speed and small power, on ac? count ofthe low bucket s peed and also because the volume of stem 1 fiowin stagepressures required t secure ahigh efficiency. In the combination which1s the su-bject of the present ll'lVl ntion, the exhaust from the engineis conne ated with the tur-.

iseniployed), so that the engine will workj between the boiler 'pressure and .apressure. which maybe for exampl: from 6 to 20 lbs. absolute,while the turbine will utilize the expansion below that p int down tothepressure of the condenser vacuum. This is the preferredarrangemen t. Asa modification, a separate set of frst' stage nozzles, adapted to expandthe stei m efliciently down to the back pressure, wil. be employed, towhich the exhaust from he engine will be throu hthe turbine is notsufiiciei it; to maintain t e delivered. But this make necessary,the'use of a-higher exhaust pr assure and lowerto utilize as much ofthe v'ailable energy as possible in the engine under these condi tionswithout covering too great a range of zxpansion.

At cruising speeds, the. direct supply of steam from the boiler to thefirst stage nozzles of the turbine will be cut oil and the entireexpansion utilized successively inthe engine and the turbine. F orhigher speeds live steam will be admitted directly to the first stagenozzles of the turbine, and will result in raising the pressure in theinitial stages of the turbine so that the engine will work against ahigher back pressure, This back pressure will inercaseas the flow ofsteam directly to the turbine is increased,

until the full speed conditions are attained, so that, although thespeed of the engine is increased, the power which it is called upon todevelop is not increased owing to the decreased range cf pressure whichit utilizes. The engine will be coupled to the shaft by a suitablecoupling so that it can be uncoupled at full power if desired, or atanytime, for

repair or other purpose without interfering with the drivin of the shaftby the turbine.

Mounted direct y upon the same shaft ,with the engine and 'go-aheadturbine is also 'a backing turbine, whose shell may be a continuation ofthe shell at the low pressure end oft-he go-ahead turbine, or a separateshell. The backing turbine is likewise and i in a similar mannerconnected with the exhaust of the engine, and also connected d1- ingturbine.

rectly with the boiler, so that the engine can be used to add to thepower of the back- A change valve is located'in the exhaust steam pipeof the engine at the point where it branches to the go-ahead and backingturbines, and this change valve is connected with the link motion of theen-- gins so that the reversing of the engine will simultaneouslyreverse the connection of its exhaust from the go'ahead turbine to thebacking turbine. A change valve may also .be used .to control the flowof live steam di-' 'rectly to the g'o -ahead and backing turbines,

and this may also .be connected with the link motion of the engine, orthe live steam con- .nections may be controlled by separate throttlevalves.

' In the. accompanying drawing" formingpart hereof,- Figurel isa sideelevationjand partial section illustrating a compound engine and turbinearranged so as to embody our invention; Fig. 2 is a top View of the.

sameparts; Fig. 3 is a vertical-section on line 33 in F1g.- 2, lookingto the ri ht;- Figs. 4: and 5 are sectional views of one orm of valvewhich maybe employed forchanging the flow of steam from the go-ahead to.

the backing turbine, and vice versa; F 6 is a plan view of a modifiedarrangement in which the live steam connections to the oahead andbacking turbine are control ed by separate valves; and Fig. 7. is a viewiledstosz showing two separate sets of nozzles for the first stage ofthe turbine.

Referring particularly to Figs. 1 to 5A is the go-ahead turbine; 13 isthe backing turbine. These may be inclosed in a single casing, as shown,and discharge in opposlte directions into the condenser Cf Each of theseturbines has initial impulse, pressure stages, with partial peripheraladmission, and a final drum stage." D is a compound steam engine. Theshaft 6, upon which the rotating elements of the turbine are mounted, itwill be understood, is connected with the propeller. The shaft .7 of theengine is coupled with the shaft 6 by aclutch 8 of any suitable form,whichmay be operated by the lever 9. The thrust block for taking thepropeller thrust is shown at 10. The pipe 11 is the steam supply pipefrom the boiler. The flow of steam through this pipe is controlledbyjthe throttlevalve 12, from which there is a connection through thevalve 13 to the high pressure chest of the" compound engine I). Thevalve 12 also controls the admission of steam to the pipe 14 whichextends to one side'of the change" valve 15. From the change valve,15 aconnection 16, provided with throttle valve 16*, is made to the steamchest 17 of the goahead turbine A; while another connect-ion 18 is madefrom the change valve 15 to the steam chest 19 of the backing turbine B;

"The exhaust from the low pressure cylinder so that the exhaust fromtheengine does not of'the compound engine passes through the valve 20,and by a pipe 21 is carried to the change valve 22. From th is changevalve there is one connection 23 extending to the.

shell of the go-ahead turbine, and entering that shell at the last wheelstage so that the steam flowing through 23 will notpass through thewheel stages of the turbine but will first enter the workin passagesofthe turbine through the nozz espreceding the drum stage. From thechange valve 22 there is another connection 24, leading to."

the first stage shell of the backing turbine,

30 with the link motion 31'for'reversing the' steaine ine.

It will e understood that when the lever 29 is in one position the linkmotion will be adjusted to cause the-engine to drive forward and at thesame time the change valves 15"and'22-wil1-be adjusted to open the pipes16 and 23 and. close the pipes 18 and 24 so that the steam will bedelivered to thego-ahead turbine and cut off from reversed and thego-ahead turbine connections 16 and 23 closed and the backing turbineconnections 18" and 24 opened.

While the valves 'permit of different methods of control, it is apparentthat the fIIiIIlBJIlOVBI canbe controlled almost wholly y the mainthrottle valve 12 and the reversing lever 29. Except when it is desiredto run. the shi than full spee will be left open and the speedcontrolled by the valve 12. When a'suflicient distance to be run at lessthan full speed to warrant the change, the valve 16* will be closed moreorless, thus cutting down the total power developed by the turbine and,particularly,-wholly or largel cutting .out the ineffective earlystages. When the valve 16 is set for any desired speed condition, lowerspeeds can :be secured by reducing the steam supply at the valve 12. Inreversing, the control is effected entirely by the main throttle valve12 and thereversing lever 29, the area of the first stage nozzles of thebacking turbine beingsuch that when the valve 12 is open, an effectivedistributionof power between the backing turbine and the engine will beproduced. i

i As shown in Fig. 6, the live steam con nections 16 and 18 to thego-ahead and back ing turbine may be controlled by separate hand valves32 and 33, whilethe connections 23 and 24 from the exhaust of theenginewill be controlled b a change valve22 connected with the lin 40 As shownin Fig. 7 a' separate steam chest 34, with nozzles, at the head of thefirst stage of the turbine, may be used to receive V the exhaust steamfrom theengine, instead of carrying this exhaust to one of the lowerv"being provided with a complete power stages of the turbine.

It will-be understood that the propeller shaft carrying a completesteamutilizing plant may furnish the entire power for driving. the ship, ormay be used in-a two or three-shaft arrangement in which the shafts areindependent of each other, each equipment of the character described.

. sion, the combination with a shaft, of a steam turbine directlycoupled thereto hav-. ing a live steam connection and adapted to What weclaim is y 1. In a prime moverfor marine propulsion, the combination ofa reclprocatlng steam engine and a steam turbine, directly coupled tothe same shaft, receiving the steam in succession and adapted to utilizethe complete expansion of the steam, substantially as set forth.

2. In a prime mover for marine propulfor some distance less. the. valves13, .20 and 16 motion of the engine.

utilize the complete expansion of the steam,- and a reciprocating steam(ngine directly, coupled to the same shaft and exhausting into saidturbine, substantial; y as set forth.

3. In a prime mover for marine propul: sion, the combination with ashaft, of a steam turbine directly couple 1 thereto, having a live steamconnection ndadapted at high powers toutil'ize the ct mplete expansionof the steam, and a recip rocating steam engine directly coupled to thesame shaft and exhausting into 'said tlrbine at low powers, said enginebeing ad: .pted to utilize the steam expansion from t] e initialpressure to. an intermediate preisure,.substantially as setforth,

4. In a prime mover for marine propul sion, the combination with ashaft, of a.

steam turbine directly coupli d there to having alive steam c(')nnection:nd adapted. to utilize the complete expanslo 1 of the steam,

and a reciprocating'steam lngine directly coupled to the same shaft :ndexhausting into said turbine at an intermediate point of its'expansionrange, subs initially as set forth.

5. In a prime mover for :narine propul sion, the combination of 2reciprocating steam engine and a steam to rbine having a fixed speedrelatlon and rece: vlng the steam in succession, such turbine ha winginitial in'1* pulse pressure stages with )artial peripheral admissionand a final d rum stage, and a direct hve steam connectior to theturbine,

substantially as set forth.

6. In a prime mover for narine propulsion, the combination of 2reciprocating steam engine and a steam turbine directly coupled to thesame shaft an dreceiving the steam in succession, such turl me having1n1 t ial impulse, pressure stages with partial peripheral admission,and a d: rect live steam.

connection "to the turbine, substantially as set forth.

connection to the turbine, :ubstantially as set forth. I

8. In a prime mover for marine propulsion, the combination ofreclprocatlng steam engine and a steam. turbine having initial impulse,pressure stag ;es with partial peripheral admission, dire tly coupled tothe same shaft, and an exh LllSt steam con" nection from "the engine tohe turbine cutting out the high pressure first stage nozzles,substantially as set" for .h.

9. In a prime mover for marine propulsion, the combination of Lreciprocating steam engine and a steam turbine having initial impulse,pressure stages with partial peripheral admission, directly coupled tothe same shaft, and'anexhaust steam connection from the engine to theturbine, cutbacking steam turbine, all coupled directlyto the sameshaft, live steam connections to both turbines. and exhaust steamconnections from the engine to both turbines, substantially as setforth. a

11.111 a prime mover formarine propulsion, the cmnbination with ago-ahead steam turbine, a backing steam turbine and a steam engine. ofexhaust steam'connections from the engine to both turbines, and meanssubject to a single control for simultaneously reversing the engine andthe exhaust connet-(ions to the turbines, substantially as set forth.

12.v In a prime mover for marine propulit'n. the -on'ibination with ago-ahead steam turbine, a backing steam turbine and a ,team

engine, of exhaust steam connections from the engine to both turbines, achange valve controlling the two exhaust connections and a connectionbetween the change valve and the link motion of the engine,substantially as set forth.

13. In a prime mover for marine propulsion, the combination with ago-ahead steam turbine, a backing steam turbine and a steam engine,oflive steam connections to both turbines and to the engine, exhaustconnections from theengine to both turbines and means subject to asingle control for simultaneousl; reversing the engine and the live andexhaust turbine connections, substantiallv as set forth.

This specification signed and witnessed.

CHARLES G. CURTIS.

RALPH L. LOVELL.

\Vitnesses to the signature of Charles G. Curtis:

- H. PELOUBE'I,

JOHN L. Lorscl-i.

Vitnesses to the signature of RalphL. Lovell:

AxsELo CONTI, \VnsLnv' RHODES.

